GUEST EDITORS' INTRODUCTION

by Greg Thompson and Yih-Farn Robin Chen

June 2009 IPTV—Reinventing Television in the Internet Age

The Internet has evolved from a dial-up command line childhood into a broadband, visually rich adolescence. However, in many ways it's still handicapped by its laissez-faire heritage. Video—the most powerful visual multimedia format—requires significantly higher bandwidth, quality of service, reliability, scalability, and security than Internet's best-effort legacy might be able to provide. This has led service providers to embark upon major investments in new Internet protocol (IP) networking technologies to better support video while also developing a new form of television (TV) called IPTV. They're looking to marry the high level of visual quality and reliability expectations of digital TV with the interactivity, flexibility, and rich personalization that IP technology enables.

IPTV is not just about delivery of digital television over Internet technology; it's about creating a video-centric and visually compelling next generation of the Internet that's accessible on any device—be it mobile phone, computer, or high-definition TV (HDTV)—at any time and place. It's about leveraging the power of the Internet to better navigate the flood of content flowing our way. And it's about reinventing television advertising from being an unwelcome interruption to providing useful, relevant information that can help make our lives more productive and fulfilling.

Some think that these lofty goals make IPTV the next killer application for the Internet. We disagree. IPTV is primarily a platform to better enable future killer applications, including those yet to be invented. It defines how to reliably and securely integrate video, including broadcast TV, targeted advertising, and video-on-demand (VOD), into flexible applications that can leverage the power and technology of the Internet. It does this while also optimizing its user interface for a wide variety of devices.

Video and IPTV have become the catalysts to bring together the requirements, technologies, architectures, services, protocols, organizations, and people to advance the development of the Internet and the service-provider networks that form it. And this is what's finally driving the deployment of IPv6—the scaling of mobile phone networks, the integration of consumer electronics, and the attention of the studios looking for better direct channels to tell their stories.

Telecommunication service providers find that video content and mobility are the key services consumers value and are willing to pay for. Being new to video and the multichannel video programming distributor (MVPD) market, they look to use IPTV's advanced capabilities to differentiate themselves from established video providers. They also look to integrate their new video capabilities with their existing mobility leadership.

But IPTV isn't just limited to telecommunication networks. Although they might not use the same term, cable and satellite television networks are rapidly evolving to IP technology as well. Next-generation cable set-top boxes (STBs) have embedded cable modems enabling greater interactivity, higher bandwidth IP communications, real-time application downloads, and even IP-delivered video simultaneously with direct 256-QAM video delivery over cable.

Satellite providers find they can enable next-generation functionality as well through hybrid designs that marry a broadband Internet connection with satellite delivery. Along with the cable or multiple-systems operators (MSOs), satellite providers are updating their backbone networks to IP technology.

All this made selecting only six articles to cover the broad topic of IPTV almost impossible. But we feel the following six articles will give you a sampling of the different areas IPTV addresses and whet your appetite for learning more about it and its future capabilities.

"Designing a Reliable IPTV Network," by Robert Doverspike and his colleagues at AT&T Labs, describes the challenges of designing an IP transport network as well as restoration and video packet recovery methods that can achieve the stringent quality of service (QoS) required for IPTV services delivered using IP multicast. It proposes using fast reroute (FRR) in harmony with IP routing and other packet protocols to address the challenges and provides a good overview of how service providers are updating their networks to support next-generation IPTV services.

"Standardization Activities for IPTV Set-top Box Remote Management," by J.S. Wey, Joachim Lueken, and Juergen Heiles of Nokia Siemens Networks, discusses two important areas for IPTV: STBs and their remote management over the network. STBs interfacing to HDTVs are like mobile phones—the front battle lines for IPTV—generating user experiences so critical to IPTV's success. STBs are enabled by continued advancements brought on by Moore's law, but their sheer numbers frequently make them the most expensive part of any IPTV network; their cost would balloon out of control if they couldn’t be managed and supported remotely. This article provides an overview of the various international standards efforts behind the development of effective remote management standards for STBs.

Mobile TV promises to further enrich the TV experience by letting consumers not only watch TV on the move, but also have access to personalized, time-shifted, and on-demand TV. In "Digital Television for Mobile Devices," Jiehan Zhou and his colleagues from the University of Oulu survey existing mobile TV technologies and analyze the technical characteristics for each mobile TV solution, discuss specifications and standards, and present possible developments.

"Not All Packets are Equal" is a two-part article by Jason Greengrass, John Evans, and A.C. Begen of Cisco Systems. In the first part, the authors consider network factors that impact the viewers' quality of experience (QoE) for IP-based video-streaming services such as IPTV. They describe the IP service-level requirements for a transported video service and explain MPEG encoding to help readers understand the impact that packet loss has over QoE. In the second part, they highlight the impact that different durations of IP packet loss have on QoE for IP-based video-streaming services. They describe the visual impairments that result from such packet losses and present the results of testing and analysis to compare impairments for different loss durations for both MPEG2-encoded standards and high-definition services.

"Reducing Channel Change Times in IPTV with Real-Time Transport Protocol," by A.C. Begen, Neil Glazebrook, and William Ver Steeg, also of Cisco Systems, highlights a specific requirement for IPTV—providing a user experience that meets or exceeds expectations. Consumers have grown up with effectively instantaneous access to analog broadcast television and expect a similar experience with digital television and IPTV. Because of the nature of secure delivery of highly compressed digital video streams over an IP network, providing rapid random access to an unlimited set of IPTV video streams is nontrivial. This article discusses how to provide rapid and consistent channel change times through the use of standard Real-Time Transport Protocol (RTP) in an IPTV network.

As secure and reliable IPTV-based content delivery becomes established and as broadband bandwidth continues to increase, savings associated with direct delivery over the network will outweigh the costs associated with distributing physical DVD or Blue-Ray media. Thus, IPTV will likely emerge as the new preferred channel over which studios distribute their products. We can therefore expect IPTV to start improving how we all enjoy, learn from, and engage with television in the 21st century—and perhaps help achieve what David Sarnoff outlined in his original vision for TV:

When television has fulfilled its destiny, humanity's sense of physical limitation will be swept away, and boundaries of sight and hearing will be the limits of the Earth itself. With this may come a new horizon, a new philosophy, a new sense of freedom and greatest of all, perhaps a finer and broader understanding between all the peoples in the world.

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